ABSTRACT: With the development of an IT (Information Technology) society, the opportunity to use electronic devices, such as cell phones and personal computers, has increased. These electronic devices pro-vide many benefits to society. However, there have been a number of reports of electromagnetic hypersensitivity (EHS) related to the use of electronic devices. The symptoms of EHS may include headaches, fatigue, tinnitus, dizziness, memory loss, irregular heartbeat, and skin trouble. Since the pathogenic mechanism of such conditions is not yet clear, further research is required. This report shows how a subject’s dizziness and joint mobility disorder, caused by electromagnetic waves emitted by electronic devices, were cured by removing an onlay from the patient’s mouth and replacing it with a gold alloy onlay. The result indicates that the subject’s symptoms were caused by EHS. Although the symptoms were improved after the dental treatment, the underlying mechanism of the symptoms and the reason why this treatment is successful remain unclear. Further research is required to clarify these issues.